The health benefits of running, jogging and walking are widely known and have been well documented. An entire industry of sporting footwear, running apparel, and related periodical publications dedicated to enhancing these forms of exercise, has arisen in recent years, with the result of highly comfortable, shock absorbing footwear being available globally. These products share a common benefit over traditional footwear, namely increased cushioning or resilience without undue loss of lateral stability. The means by which this resilience is accomplished is almost universally the employment of elastomeric foam (air entrained in various elastomeric materials), or air bags, or both, for cushioning, typically in conjunction with somewhat oversized (principally overly wide) sole areas to offset the decreased lateral stability that the introduction of the cushioning material involves. Limitations of these traditional approaches in providing for increasing cushioning with operational safety include 1.) the rising spring rate inherent to elastomer-based compression springs, and 2.) the limited travel magnitude that can be employed before incurring excess loss of lateral stability. Numerous inventive proposals to increase shock absorption and resilience, over those of the so-called miming shoe, have been patented, some of which include efforts to deal with the loss of lateral stability inherent to the various cushioning mechanisms. None, however, provide practical (quiet, lightweight, and robust vs. wear) mechanisms for storing and releasing the kinetic energy of a runner's stride while dealing with the increased ankle-turning roll moment due to increased foot elevation, above the ground at impact, that increased cushioning travel entails, and while also providing for direction-of-travel motion control similar to that inherent to the human body's design architecture. Accordingly, there exists a need to overcome these current art limitations in order to improve both safety and enjoyability of these very beneficial forms of physical exercise, with the concurrent benefit of reduced impact loading magnitudes.
Lateral is defined herein as sideways, or in the transverse direction, where “Longitudinal” is defined as the fore-aft direction as typified by the long axis of the foot, and the direction of normal forward travel. For purposes of this text, “Pitch” or Pitching” is defined in common with aircraft terminology, as rotation about a transverse or lateral axis, i.e. in a forward rolling mode; “Roll” or “Rolling” is defined as tilt in the lateral direction, or rotation about a longitudinal axis, while “Yaw” will be understood to be rotation about a substantially vertical axis.